I love Mac OS X. Honest. It's gorgeous, it's reliable, it's got most of what I like about UNIX under the hood, and an actual consistent user interface on top. Not the best GUI I've used, but consistency is more important than being 100%.

But dang, that purdy GUI chews up the CPU.

That's why I call the Mac OS X login screen the 'Blue Screen of Debt', in honor of what it does to your Visa balance if you want a Mac fast enough to avoid Quartz Lag.

But, you say, I don't see any Lag on mine!

OK, let's take this quick quiz...

1. When you click on a menu, how long before the menu shows up?

   A. It's instant, no matter what application I'm running.
   B. It varies, sometimes it's instant, sometimes it can take half a second, rarely a couple of seconds.
   C. It varies, depending on the application, sometimes it can take several seconds.
   D. There's always a detectable delay, but never more than a second or two.
   E. I don't click on menus with more than a couple of dozen elements unless I need to stretch my legs.

2. When clicking on a scrollbar in a Finder window, how long does it take to respond?

   A. It's instant, no matter what.
   B. It's instant, unless I've got a lot of applications running or the window is several pages long.
   C. There is a noticable delay, particularly on large folders, but never more than a few seconds.
   D. It's always at least a second, sometimes longer.
   E. Those things aren't just decorative?

3. What happens when you minimize or unminimize an application?

   A. Totally smooth Genie effect, it's sweet.
   B. Genie's OK, but it's only smooth with Scale.
   C. It's like watching an old movie, it looks OK but it's never smooth.
   D. I can get a couple of frames of Scale showing, Genie slows things down too much.
   E. I thought that button was the "demonstrate candy colored spinner" effect.

4. In Quicktime, how large a movie can you watch.

   A. Full screen, totally smooth, I told you it was sweet.
   B. It gets a little jerky at "full sceen".
   C. It gets jerky at "full size".
   D. If I don't run most movies at "half size" they're too jerky to watch.
   E. Movies? I thought that was just an audio player. You mean that black square's supposed to be a movie?

Score:

1. Mostly A: I gotta get me a G5.
2. Mostly B: I could live with that.
3. Mostly C: Definite "Quartz Lag".
4. Mostly D: You're me.
5. Mostly E: Yeh, I tried running OS X on a Pre-G3 once too.

But, I hear, 'Modern operating system', 'It's not that bad', 'You can't expect...'

Yeh, I do expect better performance than that. I get less lag with Windows 2000 on a Pentium-not-even-MMX-133 laptop.

And it's not the OS:

I've got a NeXTStation Mono here. It's got a 68040 at 25 MHz and 32M RAM. It's almost exactly equivalent to a Performa 475 in CPU and RAM, though it's got a better SCSI controller and video... but it's definitely slower than *any* Powermac, all the way back to a 61xx.

It's running pretty much the same OS, except it's using Display Postscript instead of Quartz.

1 - A (in fact I can't recall EVER seeing delay before bringing up a menu before, all the way back to the original Mac 128),
2 - A,
3 - C (it only does frame animations, but it does them smoothly),
4 - E (the CPU's barely up to decoding an MP3 let alone video).

But the GUI is in general much faster and more responsive than on my G3/400.

You can avoid Quartz Lag, sure. It just takes money.

Embrace the Blue Screen of Debt.